<span>Answer:
The HCl and KOH will react until one or the other is gone. As you have a larger volume of an equal concentration of HCl, the KOH will go first.
moles HCl = 0.04000 L * 0.100 M = 0.00400 moles
moles KOH = 0.02500 L * 0.100 M = 0.00250 moles
moles HCl left = 0.00400 - 0.00250 = 0.00150 moles
Your total volume is now 65.00 mL, so the [HCl] = 0.00150 moles / 0.06500 L = 0.0231 M = [H+]
pH = -log [H+] = -log (0.0231) = 1.64</span>
Moles of helium is required to blow up a balloon to 87.1 liters at 74 C and 3.5 atm is 021.65 mole
Mole is the unit of amount of substances of specified elementary entities
According to the ideal gas law he number of moles of a gas n can be calculated knowing the partial pressure of a gas p in a container with a volume V at an absolute temperature T from the equation
n =pV/RT
Here given data is volume = 87.1 liters
Temperature = 74 °C means 347.15 k
Pressure = 3.5 atm
R = 0.0821
Putting this value in ideal gas equation then
n =pV/RT
n = 3.5 atm×87.1 liters / 0.0821 ×347.15 k
n = 021.65 mole
Moles of helium is required to blow up a balloon to 87.1 liters at 74 C and 3.5 atm is 021.65 mole
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